I have a 2009 flagstaff 246D. The image I have here is what I screwed off the inlet side of my water pump. I looks like some kind of filter. What is this? Where I unscrewed this from, can this be were I connect a hose to winterize with antifreeze? If so will a regular size hose screw onto this? If not, it doesn't look very easy to actually get to the actual water inlet hose connection. Also the Flagstaff owners manual says there is a inline water filter. I cant find it anywhere. Where would the water filter be located? Thanks!